Importing a vdev copied zpool from file

Gary Palmer gpalmer at
Thu Mar 26 14:07:58 UTC 2020

On Thu, Mar 26, 2020 at 08:59:17AM -0400, mike tancsa wrote:
> On 3/25/2020 7:29 PM, Attila Nagy wrote:
> > Hi,
> >
> > I'm wondering, why this doesn't work and what could be done to make it work?
> >
> > # dd if=/dev/da0 of=/data/da0
> What if you add the step
> mdconfig *-o async*??-t vnode -f /data/da0
> and then try the import ? Note, the async option adds a pretty big speed
> increase

At least on 11.3, that option has this caveat in the man page:

     -o [no]option
             Set or reset options.

                     For vnode backed devices: avoid IO_SYNC for increased
                     performance but at the risk of deadlocking the entire

Not sure if the risk of deadlocking the kernel is still there or if it's
worth any potential speedup



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